Metal–organic structures have great potential for practical applications in many areas. However, their widespread use is often hindered by time-consuming and expensive synthesis procedures that often ...involve hazardous solvents and, therefore, generate wastes that need to be remediated and/or recycled. The development of cleaner, safer, and more sustainable synthesis methods is extremely important and is needed in the context of green chemistry. In this work, a facile mechanochemical method involving water-assisted ball milling was used for the synthesis of MOF-303. The obtained MOF-303 exhibited a high specific surface area of 1180 m2/g and showed an excellent CO2 adsorption capacity of 9.5 mmol/g at 0 °C and under 1 bar.
So far it is difficult to achieve both a high graphitization degree and uniform mesopores in carbons, especially via a sustainable synthesis approach. This work shows that mesoporous graphitized ...carbons predominantly composed of amorphous and/or partially graphitic carbon nanotubes can be obtained by a simple mechanochemical synthesis using tannins as carbon precursors, iron salt as a graphitization catalyst and block copolymer as a soft template. The one-pot synthesis relied on the fast ball milling of a Pluronic-type template, tannins, and iron salt, followed by the direct thermal treatment at a certain temperature (e.g., 750 °C) leading to mesoporous carbons with a high degree of graphitization (up to 75%), high specific surface areas up to 360 m2/g, and large mesopore volumes up to 0.40 cm3/g. Moreover, the procedure can be extended for the synthesis of highly porous activated carbons with uniform mesoporosity by adding potassium oxalate to the milling system. The procedure afforded activated mesoporous carbons with substantially uniform mesopores of about 7.7 nm, a high specific surface area of 1100 m2/g, a large pore volume of 0.84 cm3/g, and enhanced CO2 adsorption capacity up to 4.0 mmol/g at ambient conditions. This synthetic approach offers advantages in terms of scalability, simplicity, and reduced environmental impact in comparison to traditional synthesis methods.
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•A facile mechanochemical synthesis of highly mesoporous graphitized carbons.•Iron salt plays a double role, i.e., as a graphitization catalyst and porogen.•Potassium oxalate protects uniform mesopores in activated carbons.•The enhanced CO2 adsorption up to 4.0 mmol/g at 1 bar and 25 °C.
A facile ball milling process was used to obtain mesoporous crystalline γ-alumina with high specific surface area up to 389 m2 g−1 and large pore volume up to 1.55 cm3 g−1 from boehmite. First ...boehmite particles were efficiently dispersed into small nanocrystals, which was achieved by using ball milling with addition of a small amount of diluted nitric acid. Such pulverized alumina precursor showed the ability to self-assemble in the presence of block copolymer into mesostructures upon continued milling. Next, the direct mild thermal treatment was used to remove polymeric micelles and achieve the desired crystallinity. The as-obtained mesoporous crystalline γ-alumina is highly suitable for several applications such as catalysis and adsorption.
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•Research Highlights:•Mesoporous crystalline alumina with high surface area and uniform porosity.•A facile ball milling preparation of boehmite small nanocrystals.•Block copolymer-assisted assembly of boehmite into mesostructures upon milling.
The objective of the study was to determine the effect of high hydrostatic pressure (HHP) on quality of cryopreserved semen of young bulls. Semen for this study was collected from 8 bulls aged ...between 13 and 18 months at monthly intervals, from June to September. After collection, semen was diluted in a commercial Bioxcell
extender (one part at 1:1 and a second part to give a sperm concentration of 20 million/0.2 mL), filled into straws and treated with HHP at 30 MPa for 90 min. After HHP treatment, pre-diluted semen (1:1) was diluted to a sperm concentration 20 million/0.2 mL and filled into straws. In addition, part of the semen diluted to a concentration of 20 million/0.2 mL was not treated with HHP (control). All of it was held at +4°C and frozen in a freezer after 2.5-h equilibration. Semen was thawed in a water bath at 38°C and subjected to estimation of the percentage of motile sperm both subjectively and using a computer-assisted semen analyzer and cytometric assessment of sperm cell membrane integrity. Subjective motility and fast progressive motility were significantly higher with pre-diluted (1:1) and HHP treated semen compared to control (P<0.05). No significant differences were observed in percentage of membraneintact spermatozoa between control and experimental groups. Additionally, the influence of HHP on the sperm of individual bulls was assessed. In bull number 2, the HHP treatment after semen pre-dilution significantly improved progressive motility from 54.1 to 63.4 percent (P<0.05). In bull number 4, the HHP treatment after semen pre-dilution significantly improved subjective motility, rapid motility and progressive motility by 12.5, 16.8 and 16.3 percent, respectively (P<0.05). No effect was seen for 6 bulls. It is concluded that for some bulls, the application of HHP before semen freezing may improve the cryopreservation outcome. However, this requires further research in this area, also to determine the fertilizing capacity of bull semen exposed to high hydrostatic pressure.
Highly porous activated carbons were synthesized via the mechanochemical salt-templating method using both sustainable precursors and sustainable chemical activators. Tannic acid is a polyphenolic ...compound derived from biomass, which, together with urea, can serve as a low-cost, environmentally friendly precursor for the preparation of efficient N-doped carbons. The use of various organic and inorganic salts as activating agents afforded carbons with diverse structural and physicochemical characteristics, e.g., their specific surface areas ranged from 1190 m
·g
to 3060 m
·g
. Coupling the salt-templating method and chemical activation with potassium oxalate appeared to be an efficient strategy for the synthesis of a highly porous carbon with a specific surface area of 3060 m
·g
, a large total pore volume of 3.07 cm
·g
and high H
and CO
adsorption capacities of 13.2 mmol·g
at -196 °C and 4.7 mmol·g
at 0 °C, respectively. The most microporous carbon from the series exhibited a CO
uptake capacity as high as 6.4 mmol·g
at 1 bar and 0 °C. Moreover, these samples showed exceptionally high thermal stability. Such activated carbons obtained from readily available sustainable precursors and activators are attractive for several applications in adsorption and catalysis.
In this work, we test metal–organic frameworks (MOFs) as sorbents in the solid-phase extraction (SPE) technique to determine chemical warfare agents (CWAs) and their related compounds in water ...samples. During this study, we used 13 target compounds to test the selectivity of MOFs thoroughly. Three MOFs were used: MIL-100(Fe), ZIF-8(Zn), and UiO-66(Zr). The obtained materials were characterized using FT-IR/ATR, SEM, and XRD. CWA’s and related compounds were analyzed using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). The effect of the type of elution solvent and the amount of sorbent (MOFs) in the column on the efficiency of the conducted extraction were verified. The LOD ranged from 0.04 to 7.54 ng mL−1, and the linearity range for the analytes tested extended from 0.11/22.62 (depending on the compound) to 1000 ng mL−1. It was found that MOFs showed the most excellent selectivity to compounds having aromatic rings in their structure or a “spread” spatial structure. The best recoveries were obtained for DPAA, CAP, and malathion. Environmental water samples collected from the Baltic Sea were analyzed using an optimized procedure to verify the developed method’s usefulness.
Graphene oxide/ordered mesoporous carbon (GO/OMC) nanostructures with narrow mesopore size distribution were obtained via soft-templating synthesis followed by KOH activation. Microporosity and ...mesoporosity of these composite nanostructures were additionally controlled by adjusting the amount of added GO and by post-synthesis KOH activation. Incorporation of GO into OMC structure resulted in improving adsorption uptakes of benzene and hydrogen, which reached 9.6 mmol/g (at 20 °C and pressure close to the saturation vapor pressure) and 11.7 mmol/g (2.3 wt% H2 at −196 °C and 760 mm Hg), respectively. At the same conditions bare activated OMC adsorbed 8.1 mmol/g and 10.8 mmol/g of benzene and hydrogen, respectively. Also, these adsorbents showed high uptakes of CH4 (2.1 mmol/g at 20 °C and 760 mm Hg) and CO2 (6.0 mmol/g at 0 °C and 760 mm Hg). The GO/OMC composite nanostructures were characterized by nitrogen adsorption, scanning electron microscopy, Raman spectroscopy and thermogravimetry. To the best of our knowledge, this work represents the first comparative study of adsorption properties of the GO/OMC composite nanostructures toward various gases.
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•Tuning porosity of graphene oxide/ordered mesoporous carbon (GO/OMC) composites.•Adsorption properties of GO/OMC nanostructures toward H2, C6H6, CH4 and CO2.•Enhancement of H2 and C6H6 adsorption on OMC by adding graphene oxide.
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Striving to achieve greater efficiency in technological processes is driven by the growing demand for chemicals, but also by increasing environmental regulations. Mesoporous materials ...have great potential to be used as catalysts, carriers, and sorbents to improve the effectiveness of miscellaneous processes in the chemical industry. These materials are usually synthesized in powder form and must be shaped prior to use in industrial systems. The challenges with scaling up production of solids and problems with transforming powdered materials into technical bodies are generally underrated in scientific literature. The present review aims to summarize the most common procedures for manufacturing shaped mesoporous materials (including 3D printing) customized to the prospective applications. The focus is on the most popular mesoporous oxides such as silica and alumina, although the presented shaping strategies can be adapted to other mesostructured materials. This review demonstrates the effect of the molding procedure, binder incorporation, and other components on the performance of shaped mesoporous materials.
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•Ultrasonication affords new Pt-graphene oxide-ZIF-8-derived carbon composite.•This composite shows high surface area and substantial micro- and mesoporosity.•Its H2 uptake at room ...temperature is enhanced due to the spillover mechanism.•ZIF-8-derived carbon adsorbs more CO2, CH4 and H2 than the parent ZIF-8.
Ultrasonication is used to obtain new nanoporous composites consisting of Pt-decorated graphene oxide (Pt-GO) and zeolitic imidazolate framework (ZIF-8)-derived carbon with improved surface and structural properties as evidenced by high hydrogen uptake of 0.44 mmol/g at 25 °C and 1 bar. At the same conditions, the bare ZIF-8-derived carbon (CZIF-8) and ZIF-8 showed hydrogen uptakes of 0.13 mmol/g and 0.05 mmol/g, respectively. This significant enhancement in hydrogen adsorption on Pt-GO/CZIF-8 is attributed to spillover mechanism. Moreover, adsorption affinity of CZIF-8 toward diverse gases is examined. CZIF-8 adsorbed larger amounts of CH4 (1.8 mmol/g at 20 °C), CO2 (5.7 mmol/g at 0 °C) and H2 (9.9 mmol/g at cryogenic temperature) at 1 bar in comparison to those obtained for parent ZIF-8. This study shows that the ultrasonication-assisted coupling of Pt-GO and MOF-derived carbons can be used for fabrication of composites with tailored surface and structural properties for adsorption, catalytic and photocatalytic applications.
A facile mechanochemical method was used for the synthesis of ordered mesoporous carbons (OMCs) with well-dispersed metal nanoparticles. The one-pot ball milling of tannins with a metal salt in the ...presence of a block copolymer followed by thermal treatment led to Ni- or Pt-embedded OMCs with high specific surface areas (up to 600 m2·g−1) and large pore volumes (up to ~0.5 cm3·g−1). The as-prepared OMC-based samples exhibited hexagonally ordered cylindrical mesopores with narrow pore size distributions (average pore size ~7 nm), which implies sufficient long-range copolymer-assisted self-assembly of the tannin-derived polymer upon milling even in the presence of a metal salt. The homogenous decoration of carbons with small-sized metal (Ni or Pt) particles was essential to provide H2 storage capacities up to 0.33 wt.% at 25 °C and under 100 bar. The presented synthesis strategy seems to have great potential in the practical uses of functionalized polymers and carbons for applications in adsorption and catalysis.
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